The present embodiment relates generally to a sealing composition for sealing a subterranean zone penetrated by a well bore.
In the drilling and completion of an oil or gas well, conventional means are used to isolate the well bore into subterranean mes. Thereafter, the undesirable migration of fluids between zones is prevented. However, over the life of the well, tectonic events, changes in pressure or temperature in the well bore, and the development of problems involving undesirable formations in the zones, can result in compromised mal isolation.
Likewise, a zone in a well may begin to produce undesirable fluids, such as gas or water, which requires a remedial shut off operation. Using a diversion technique, a shut off fluid used to prevent or cure compromised anal isolation is forced into sequences of relatively lower permeability in the zone by “diverting” the fluid from sequences of relatively higher permeability. Without diversion, the sequences of relatively higher permeability would receive all of the treatment fluid.
In the past, diversion techniques used for shut off operations relied on timing fluid gelation, varying injection rate, and increasing fluid viscosity. However, a sealing composition having superior sealing properties is desirable for diversion techniques and other remedial operations.